660 THE POPULAR SCIENCE MONTHLY. 



means of a long iron bar called a paddle, and finally separates the 

 whole mass of iron into large lumps, each weighing from 60 pounds 

 upward. After this, the opening in the door of the furnace is closed, 

 and the hot oxidizing flame allowed to impinge upon the halls until 

 they are completely converted into bar-iron. The balls are then 

 placed under a hammer ; and, the melted slag being forced out, they 

 are rolled into bars between the puddling -rolls. 



The ancient mode of refining iron needed no rolls, a hammer was 

 sufficient ; nowadays, the huge quantities of refined iron turned out 

 by the puddling-furnace require more than a hammer. The invention 

 of the puddling-rolls was the natural sequence of the puddling-fur- 

 nace. This furnace yields more than a hundred times the quantity of 

 bar-iron produced by the bloomery of former times ; and the blooms 

 or balls can be made of a size sufficient to be turned into iron rails 

 of from 16 to 24 feet in length. 



At this point let us cast a glance upon the past. We are contem- 

 poraries of the great discovery which shortens the distances upon 

 the globe. About forty years have passed since the first locomotive 

 dashed over the track, and already our social and political conditions 

 are mainly dependent on this invention. Not many years ago, a 

 whole army was conveyed from the southern part of Germany to the 

 north within a few days, and this without a straggler an operation 

 formerly requiring months. In 1866 we saw how an army, equal in 

 size to the one that perished in Russia in 1812, started from the far- 

 thermost limits of Germany, was moved in a very short period to 

 another field, and arrived there at the appointed time. Within a day 

 or so, Germany or France can be passed over in its longest extent. 

 The rapid supply of local wants by the importation of grain and cat- 

 tle acts most powerfully upon the stability of prices. A famine, in the 

 proper sense of the word, can scarcely be thought of at the present 

 time, unless it be a universal famine. Fresh sea-produce, which for- 

 merly gladdened only the coast-land, penetrates now into the interior. 

 Districts far remote from the commerce of the earth, but crossed by 

 the iron track, can now take their produce to the great markets of the 

 world. Hence it cannot be denied that the form of modern society 

 depends upon the railroads. But where would our railroads be if we 

 could not roll rails? Where the rails, if we had no puddling-fur- 

 nace? Where the puddling-furnace, without a knowledge of the 

 flame ? And this knowledge is simply the result of the study of 

 chemical science, which, in turn, may be traced back to the discovery 

 of oxygen. This whole series of wonderful effects and causes dates 

 from that glass of water in which Priestley first collected oxygen. 

 Not a member of that series could have been passed by, not a link of 

 that chain been wanting, without rendering impossible the remaining 

 links. It can be asserted fearlessly, that the favorable condition of 

 modern society has its rise in the discovery of oxygen. 



